In a world where 'Soulmates', otherwise known as Darlings have the exact same branding over their heart's given to them by the government as babies you'd think there would be less heartbreak but some don't ever meet their Darlings, usually due to a death so they couple with someone else who never found theirs either, known as a Platonic. Poppy Hart is twenty two and running out of time to find her Darling. When she fails to do so, she is assigned a Platonic, her best friend West who has also lost his Darling. Three years later when the government allocate Poppy a job at Hellbound Maximum Security Penitentiary as a guard, she discovers her long-lost Darling is violent inmate Hex Rose and everything she thought she knew is turned upside down in a matter of seconds. *mature & language warning*

The world is split in two by a fence separating the upper Class and the lower Lawless societies. Class are raised to hate Lawless, believing them to be dangerous and uncivilised, with the exception of Dove Amor. It's one thing when she begins to question the morals of Class and another when Sage Creed appears in her bedroom one night, holding a knife to her neck when he gets caught on the wrong side of the fence. *mature & language warning*